Process of making sulfur trioxid.



UNITED sTArns PA T NT OFFICE;

KURT ALB EBT, 0F WIESBADEN, GEB-MANY.

PROCESS OF MAKING SULFUR TRIOX ID.

1 ,018 ,402. No Drawing.

T 0 all tvhom it may concern:

Be it knownthat I, KURT ALBERT, a subject of the Emperor of Germany, and re'si The present invention relates to the.

manufacture of sulfur trioxid, and particularly to. the contact method, whereby sulfur dioxid is oxidized to sulfur trioxid in the presence of a suitable cat'alyzer and at ap propriate temperatures, and consists in the manufacture of such acid by the use of a particular catalyzer which I have d1SCOV- ered is very advantageous-when used in this process. Ferric oxid from pyrites burners has been extensively used in' the production of sulfuric acid by the contact method, butthe temperatures at which such catalyzer best operates are from 600 C. to 620C, and at such .temperatures approximately only yield is obtained, while beneath 600 (1., the transformationof sulfur di-' oxid'into sulfur trioxid is very slight. This catalyzer too, is verysensitive to-moisture.

I have discovered that the combination hereinafter described of ferric peroxid with oxids of the alkaline earths make excep tionally good catalyzers .in the process of manufacturing sulfuric acid, and that'with the use of such catalyz ers approximately 94% yield may be obtained and at temperatures much lower than those necessary in the use of ferric oxid.

Mixtures of ferric oxid with oxids of the alkaline earths absorb oxygen when heated in a current of air or oxygen and form combinations such as those above referred to Borch.) By the use of-such a combination,

(for example) FeO .SrO I have found that 94% of. the sulfur dioxid may be transformed to sulfur trioxid'at a temperature of approximately450 C. The temperature Specification of Letters Patent.

Application filed August 2, 1911. Serial No. 641,966.

at which this process may be carried on may vary within wide limits, for example, between 400 and 640 0., but the best yleld is obtained at temperatures ranging from 450 to 550 C. Catalytic bodies 'of the above type are not so sensitive t'o moisture as the ferric oxid from pyrites burners.

In the manufacture of sulfuric acid b my process, the sulfur dioxid, together wit an oxidizing gas such as air, is pasesd in contact with the catalyzer'of the present invention at suitable temperatures and the sulfur trioxi thus obtained is converted into sulfuric acid by absorption in water.

I claim:

1. In the manufacture of sulfuric acid the process which comprises contacting sul- Patented Feb. 27,1912.

combination of ferric peroxid and an oxid- -of an alkaline earth in the presence of an oxidizing gas at temperatures sufficient to form sulfur trioxid,

2, In the manufacture of sulfuric acid the process which comprises contacting sulfur dioxid with a catalyzer comprising a combination of ferric peroxid and an oxid of strontium in the presence of air and'at temperatures sufficient to. form sulfur t-ri-- oxid.

3. In the manufacture of sulfuric acid the process which comprises contacting sulfur dioxid with a catalyzer comprising a combination of ferric peroxid and anv'oxid of an alkaline earth in the presence of air and ,at temperatures between 450 and 550 C. to form sulfur trioxid.

4.- In the manufacture of sulfuric acid the process which comprises contacting sulfur dioxid with a catalyzer comprising a combinationof ferric peroxid and an oxid of strontium in the presence of air and at temperatures between 450 and 550 C. to form sulfur t-rioxid.

In testimony whereof, I have hereunto set my hand in presence of two witnesses. v KURT ALBERT.

Witnesses:

JEAN GRUND, CARL GRUND. 

